Mumbai, Jun 20: The India Meteorological Department on Monday issued an 'orange alert' to Mumbai and Thane for very heavy rainfall till June 21.
The orange-colour coded warning for heavy rains on June 20-21 was issued for the coastal districts of Ratnagiri and Sindhudurg, the IMD said.
"Generally cloudy sky with moderate rain in city and suburbs. Possibility of heavy to very heavy rainfall at isolated places," the IMD said in its bulletin.
The IMD has four-colour coded alerts, namely green (no warning), yellow (watch), orange (alert) and red (warning).
With the fresh spell of rain, the air quality in Mumbai has increased to a "good category". According to the System of Air Quality and Weather Forecasting And Research (SAFAR), the overall AQI on Monday morning was 29.
An AQI between zero and 50 is considered 'good', between 51 and 100 is considered to be 'satisfactory', 101 and 200 is 'moderate', between 201 and 300 is 'poor', between 301 and 400 is 'very poor', and between 401 and 500 is considered to be 'severe'.